Production of 4-arylazo-5-pyrazolones



United States Patent PRODUCTIQN. 0F 4-ARYLAZO-5-B YRAZOLONES Bruce Graham, Rochester, N. Y., assignor to Eastman. Kodak Company, Rochester, N. 36., a corporation of New Jersey No Drawing. Application January 31, 1952, Serial No. 269,347

9 Glaims. (Cl. 260-163) This'inventipn relates to a method of preparing 4- arylazo--pyrazolone coloring materials.

The use of 4-azo derivatives of 5-pyrazolone as colored couplers in color photography is well known (Hanson U. S. Patent 2,449,966; Glass, Vittum and Weissberger U. S. Patent 2,455,170). These compounds have been prepared by azo coupling a diazonium salt in the 4-position of the 5-pyrazolone. This method. of Preparation has certain disadvantages. The pyrazol'on intermediates used are sometimes difiicult td prepare, particularly in a pure state and must be purified from mixtures with other compounds. Moreover, the pyrazolone intermediates are usually difficultly soluble in organic solvents.

It is, therefore, an object of the present invention to provide a novel method for the, preparation of 4- arylazo-S-pyrazolones. A further object is to provide a method for the preparation of 4-arylazo-5-pyrazolones which doesnot depend upon the use of pyrazolone intermed-iates. Other objects will appear from the following description of my invention.

These objects. are accomplished by reacting the aryl diazonium halide with a S-acyloxy pyrazole to produce the 4-arylazo-5-pyrazolone. I have also found that a similar treatment of S-pyrazolones having a 4-acyl substituent will; produce the 4-arylazo-5-pyrazolone. In fact, even the diacylated homologs, i. e., 4-acyl-5-acyloxypyrazoles, yield 4-arylazo-5-pyrazolones in the coupling reaction.

Treatment of these intermediates with the aryl diazonium salt to produce; the, 4-arylazo-5-pyrazolone is shown schematically in the following:

t that...

Soeicty as, 1495- twayy, The: S aQyIQXY G -SQYImiBQ pyrazoles as well as. the 4.-acy l6-acylamino-5-pyrazolones are produced when 4-amino-5-pyrazolones are acylated with acid chlorides or anhydrides to make compounds useful as color couplers. These compounds have hitherto been considered as contaminants in the production of 3-acylamino-5-pyrazolones. The present invention makes it possible to treat a crude acylation mixture containing 3-acylamino-5-pyrazolone, 3-acylamino-4-acyl-5- pyrazolone, and 3-acylamino-S-acy1oxypyrazole with an aryl diazonium salt to yield a single 3-acylamino-4-arylazo-S-pyrazolone.

Any aryl diazonium salt generally used to, form azo dyes by coupling with active methylene compounds or with naphthols and phenols can be used in this. synt esis.

My invention will be further illustrated by reference to the following examples, which are illustrative only.

EXAMPLE I Preparation of acyl derivatives of I-phenyl-i-methyldpymzolone (I).C. f. I. Prakt. Chem. 55, 145, 1897).

Twenty-five grams o I were dissolved in 150 cc. of acetic anhydride. and the solution refluxed for one hour. The acetic anhydride was removed and the residue disstilled at 122/l mm.,, yielding 22 g. of l-phenyl-S-methyl-5-acetoxypyrazole, II. AnaL-Calcd. for C12H12N2O2: C, 66.7; H, 5.6; N, 13.0., Found: C, 66.5; H, 5.6; N, 13.2. H is easily hydrolyzed to I by solution in cold 5% alcoholic potassium hydroxide.

Twenty-five grams of I were dissolved in a solution of 125 cc. of acetic anhydride and 25 g. of sodium acea and the mixture: refluxadtor one hour. The cooled solu ion was poured intov 8011 cc. of cold; water; The resulting brownoily: solid. coliectecl and. tritmtated with 5.0 cc. of, methyl alcohol, producing 1 11.2 g.: of, solid, melting OH;CCH:

at 90-92. This was recrystallized from 300 cc. of ligroin, yielding 9.7 g. of white needles melting at 90-92. Analysis indicated that this was 1-phenyl-3-methyl-4- acetyl 5 acetoxypyrazole, III. Anal.Ca1cd. for C14H14N2O3; C, 65.2; H, 5.4; N, 10.8. Found: C, 65.1; H, 5.5; N, 10.9.

The water-acetic acid mother liquor from the production of III was extracted with 400 cc. of benzene. The solvent was removed and the residue distilled at'l mm., giving 14.3 g., B. P. l160, of a liquid which solidified upon cooling. This material was recrystallized from 500 cc. of water and 250 cc. of ethyl alcohol to yield 12.4 g. of 1-phenyl-3-methyl-4-acetyl-5-pyrazolone, IV, melting at 6162 before drying and at 66-67 after being dried at and 1 mm. Anal.Ca1cd. for C12H12N2O2: C, 66.7;"I-I, 5.6; N, 13.0. Found: C, 67.1; H, 5.5; N, 12.9. III was readily hydrolyzed to IV by cold alcoholic potassium hydroxide. IV was not hydrolyzed to I by cold bases.

A20 coupling of acyl derivatives of I-phenyI-S-methyl- S-pyrazolone One hundredth mole quantities of I, II, III, and IV, each dissolved in 50 ml. of pyridine, ,were treated at 0 Q. with an aqueous solution of benzenediazonium chloride (0.011 mole each). All our couplers produced in good yield the same azo dye, i. e., 1-phenyl-3-methyl-4- phenylazo-S-pyrazolone,.V, M. P. 155 (cf. Knorr, Ann.,

EXAMPLE II Preparation of I-(4 cyanophenyl)-3-benzamid0-5-bcnzogcypyrazole, VI, and 1-(4 cyanophenyl) 3 benzamzdo-S-pyrazolorzg, VII

VII, by solution in two equivalents of 5% alcoholic potassium hydroxide.- Acidification precipitated VII in 70- 80% yield, M. P. 254257.

Preparation of 1-(4-cyan0phenyl-3-benzamid0-4- phenylazo-5-pyrazol0ne, VIII Pyridine solutions of VI and VII, when treated with aqueous solutions of benzenediazonium chloride at 0 C., yielded the same azo dye, VIII, melting at 258260.

Preparz ztion gf acyl derivatives of I-(4-nitr0phenyl)-3- mthyl-S-pyrazolone, IX

Twenty-five grams of IX were dissolved in a solution of--10 g. of sodium acetate in 460 cc. of acetic anhydride and the mixture was refluxed for fifteen minutes. The cooled solution yielded 18.5 g. of 1-(4-nitrophenyl)-3- methyl-4-acetyl-5-pyrazolone, X, M. P. 198202. The melting point afterrecrystallization from acetic. acid was 202203.5. AnalysisCalcd. for C12H11N3O4: C, 55.2; H, 4.2; N, 16.1. Found: C, 55.3; H, 4.2; N, 16.1. X was not hydrolyzed to IX by 'cold bases.

A similar run without the-addition of sodium acetate yielded 1 (4 nitrophenyl)-3-methyl-S-acetoxypyrazole, XI. This was isolated by drowning the reaction mixture in water and collecting the product, 25 g., M. P. 112..113. After recrystallization from benzene, XI melted at 114- 116. AnalysisCalcd. for 'C12H11N3O4: C, 55.2; H, 4.2; N, 16.1. Found: C, 55.2; H, 4.1; N, 16.3.

XI was readily hydrolyzed to IX by cold alcoholic potassium hydroxide.

Azo coupling ofacyl derivatives of 1-.(4-nitr0ph e nyl B-meIhyI-S-pyrazolone, IX

II N 01 f mm:- 5

XII

Gang-t N XIV 6 EXAMPLE 1v Freparaliom of acyl derivatives of I -phenyl-3-amino-5- pyrazolone, XIII A boiling solution. of XIII (8.75 g.) in cc. of acetonitrile was treated with 34.2 g. of 2,4-di-tert-amylphenoxyacetyl chloride. After four hours at reflux the solvent was removed. The resulting white solid was washed with solid acetonitrile or petroleum ether or both to yield I-phenyIFS-(zi-di tent-amylphenaxyacetamido)- i-pyrazolono, XIV, M. P. 20 F206.

A pyridihe solution of XIV, when treated with a 30% molar excess of 2,4-di-tert-amyiplienoxyacetyl chloride at. room temperature for 20 hours, yielded l.-phenyl- 3- (2,4 di tert amylphenexyacetamido)-4-. A-di-tertaniylphenoxyaeetyn-fi=pyrazolone, The product was obtained by drowning the pyridine solution. slowly with Water. The solid was collected and recrystallized from ligroin. It was polymorphous, having a melting rang-e G1 Recrystallization from. acetic acid resulted in a sofva'ted product. melting. at 121-123. AnalysisC'alcd. for C45He1NsO5:C2HeO: C, 72.0; H, 8.4;: N, 5.4. Found: C, 72.2; H, 8.5; N, 5.4.

Azo coupling of acyl derivatives of I-phergJJ-amino-S- pyrazaioneg. XHZ

C -oc11,ooNHo-om (MONTFCI- XVI Itwill be understood that the examples and modifications included herein are illustrative only, and that my invention is to be taken as limited only by the scope of the appended claims.

WhatIclaimis: g I

1. The methodof preparing a 4-arylazo-5-pyraz olone which comprises condensing an aryldiazonium chloride with a compound selected from the group consisting of 4- carboxyacyl 5 -'pyrazolones, S-acyloxypyrazoles, and 4-carboxyacyl-S-acyloxypyrazoles' at the. 4-position of said compound.

2. The method of-preparing a 4-arylazo-5-pyrazolone which comprises condensing an 'aryldiazonium chloride with a S-carboxyacyloxypyraZole at the 4-position of said pyrazole; A v

3. The method of preparing a4-arylazo-5-pyrazolone which comprises condensing an aryldiazonium chloride with l-phenyl-3 (2,4 diamylphenoxy)-acetarnido-4- (2",4"-diamylphenoxyacetyl)-5-pyrazolone at the 4-position of said pyrazolone. 1 i

4. The method of preparing a 4-arylazo-5-pyrazolone which comprises condensing an aryldiazonium chloride with a S-benzoxypyrazole at the 4-position of said pyrazole. V

' said pyrazolone.

8. The method of preparing a 4-arylazo-5 py'r'azolone which comprises condensing an aryldiazonium chloride with 1-p-nitr0phenyl-3-methyl-5-pyrazo1one at the 4-position of said pyrazolone.

9. The method of making a 4-phenylaZo-5-pyrazolone which comprises treating a S-acyloxypyrazole dissolved in pyridine, with an excess of a benzenediazonium chloride at about 0 C. and allowing the reaction mixture to stand at room temperature for at least one hour, thereby converting said pyrazole to said pyrazolone.

No references cited. 

1. THE METHOD OF PREPARING A 4-ARYLAZO-5-PYRAZOLONE WHICH COMPRISES CONDENSING AN ARYLDIAZONIUM CHLORIDE WITH A COMPOUND SELECTED FROM THE GROUP CONSISTING OF 4CARBOXYACYL - 5 - PYRAZOLONES, 5-ACYLOXYPYRAZOLES, AND 4-CARBOXYACYL-5-ACYLOXYPRAZOLES AT THE 4-POSITION OF SAID COMPOUND. 